I chose Jenassa as a follower because I knew here AI was programmed for her to keep her distance and use the bow. This was working quite well for a while until at a certain point she just started using sword and shield only. No matter what we are fighting now she only uses sword and shield. Her inventory currently has two forsworn swords, an elven shield, a dwarven bow and zephyr. Has this happened to anyone and do you think it has something to do with the forsworn swords? It might have started around the time I gave her those swords.

I'd try removing the swords and the shield from her inventory first, if that doesn't work, I think you can speak to her and order her to use her bow only.

Hope that helps.